I just came across probably the single coolest science video I have seen in ages: a six minute excerpt from the documentary Ants: Nature's Secret (which won the special jury prize at the Jackson Hole Wildlife Film Festival in 2005). The documentary itself focuses on the work of Bert Hölldobler (who co-wrote the Pulitzer-prize winning The Ants with E. O. Wilson), but the excerpt (embedded below, or click here to go to YouTube) features Walter Tschinkel's amazing cement cast of an entire ant colony. (The cement technique itself seems to have been pioneered by Moreira et. al.). I highly recommend watching the video - it gets especially interesting after about 2 minutes.
(See also: ABC's article on Tschinkel's work, BLDG Blog's fantastic entry on Nest-Casting, and Ask a Biologist's podcast interview with Hölldobler in which he discusses the documentary [click here for the mp3]).